AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31
Description: Ask Around Me - Example application

Parameters:
  QuestionsTableName:
    Type: String
    Description: Name of Questions DynamoDB table
    Default: aamQuestions

  QuestionsTableStreamARN:
    Type: String
    Description: Stream ARN for Questions DynamoDB table
    Default: EnterYourStreamARN 

  AnswersTableName:
    Type: String
    Description: Name of Answers DynamoDB table
    Default: aamAnswers

  IoTDataEndpoint:
    Type: String
    Description: The IoT data endpoint for the application.
    Default: YourIOTendpoint

  Auth0issuer:
    Type: String
    Description: The issuer URL from your Auth0 account.
    Default: https://dev-xxxxxxxx.us.auth0.com/

Globals:
  Function:
    Timeout: 5
    Runtime: nodejs12.x
    Tags:
      Application: AskAroundMe

Resources:
  # HTTP API
  MyApi:
    Type: AWS::Serverless::HttpApi
    Properties:
      # HTTP API authorizer - see https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-property-httpapi-httpapiauth.html
      Auth:
        Authorizers:
          MyAuthorizer:
            JwtConfiguration:
              issuer: !Ref Auth0issuer
              audience:
                - https://auth0-jwt-authorizer
            IdentitySource: "$request.header.Authorization"
        DefaultAuthorizer: MyAuthorizer

      # CORS configuration - this is open for development only and should be restricted in prod.
      # See https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-property-httpapi-httpapicorsconfiguration.html   
      CorsConfiguration:
        AllowMethods:
          - GET
          - POST
          - DELETE
          - OPTIONS
        AllowHeaders:
          - "*"   
        AllowOrigins: 
          - "*"   

  # Functions handling user answers
  GetAnswersFunction: 
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: answers/      
      Handler: get.handler
      MemorySize: 128
      Description: Get all answers for a question
      Policies:
        - DynamoDBReadPolicy:
            TableName: !Ref AnswersTableName     
      Environment:
        Variables:
          AWS_NODEJS_CONNECTION_REUSE_ENABLED: 1
          TableName: !Ref AnswersTableName  
      Events:
        Get:
          Type: HttpApi
          Properties:
            Path: /answers/{Key}
            Method: get
            ApiId: !Ref MyApi     

  PostAnswersFunction: 
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: answers/      
      Handler: post.handler
      MemorySize: 128
      Description: Post new question to an SQS queue
      Policies:
        - SQSSendMessagePolicy:
            QueueName: !GetAtt StarAnswersQueue.QueueName    
        - SQSSendMessagePolicy:
            QueueName: !GetAtt GeoAnswersQueue.QueueName               
      Environment:
        Variables:
          StarQueueURL: !Ref StarAnswersQueue          
          GeoQueueURL: !Ref GeoAnswersQueue      
      Events:
        Post:
          Type: HttpApi
          Properties:
            Path: /answers
            Method: post
            ApiId: !Ref MyApi        

  DeleteAnswersFunction: 
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: answers/      
      Handler: delete.handler
      MemorySize: 128
      Description: Delete a single answer      
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref AnswersTableName
      Environment:
        Variables:
          AWS_NODEJS_CONNECTION_REUSE_ENABLED: 1
          TableName: !Ref AnswersTableName
      Events:
        Delete:
          Type: HttpApi
          Properties:
            Path: /answers
            Method: delete
            ApiId: !Ref MyApi  

  ProcessAnswerStarFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: answers/processAnswerStar/
      Handler: app.handler
      MemorySize: 128
      Description: Processes SQS queues for incoming star rating answers.      
      Timeout: 10
      ReservedConcurrentExecutions: 1
      Environment:
        Variables:
          TableName: !Ref AnswersTableName
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref AnswersTableName
      Events:
        MySQSEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt StarAnswersQueue.Arn
            BatchSize: 10            

  ProcessAnswerGeoFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: answers/processAnswerGeo/
      Handler: app.handler
      MemorySize: 128
      Description: Processes SQS queues for incoming geo answers.      
      Timeout: 10
      ReservedConcurrentExecutions: 1
      Environment:
        Variables:
          TableName: !Ref AnswersTableName
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref AnswersTableName
      Events:
        MySQSEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt GeoAnswersQueue.Arn
            BatchSize: 10   

  ## Lambda functions processing DynamoDB streams
  ProcessAnswersStreamFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: streams/processAnswers/
      Handler: app.handler
      MemorySize: 128
      Description: Aggregates answers data from DDB stream  
      Timeout: 10
      ReservedConcurrentExecutions: 1
      Environment:
        Variables:
          TableName: !Ref QuestionsTableName
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref QuestionsTableName
      Events:
        Stream:
          Type: DynamoDB
          Properties:
            Stream: !GetAtt AnswersTable.StreamArn
            BatchSize: 100
            StartingPosition: TRIM_HORIZON

  ProcessQuestionsStreamFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: streams/processQuestions/
      Handler: app.handler
      MemorySize: 128
      Description: Updates IoT topics with changes to Questions DDB table        
      ReservedConcurrentExecutions: 1
      Environment:
        Variables:
          IOT_DATA_ENDPOINT: !Ref IoTDataEndpoint
      Policies:
      - Statement:
          - Effect: Allow
            Resource: '*'
            Action:
              - iot:*
      Events:
        Stream:
          Type: DynamoDB
          Properties:
            Stream: !Ref QuestionsTableStreamARN
            BatchSize: 100
            StartingPosition: TRIM_HORIZON

  # Functions handling user questions
  PostQuestionFunction: 
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: questions/post/            
      Handler: app.handler
      MemorySize: 128
      Description: Post new question to an SQS queue
      Policies:
        - SQSSendMessagePolicy:
            QueueName: !GetAtt QuestionsQueue.QueueName             
      Environment:
        Variables:
          QueueName: !Ref QuestionsQueue   
      Events:
        PostQuestion:
          Type: HttpApi
          Properties:
            Path: /questions
            Method: post
            ApiId: !Ref MyApi

  GetQuestionsFunction: 
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: questions/get/            
      Handler: app.handler
      MemorySize: 2048
      Description: Returns list of questions from lat/lng query params
      Policies:
        - DynamoDBReadPolicy:
            TableName: !Ref QuestionsTableName      
      Environment:
        Variables:
          AWS_NODEJS_CONNECTION_REUSE_ENABLED: 1
          TableName: !Ref QuestionsTableName
      Events:
        GetQuestions:
          Type: HttpApi
          Properties:
            Path: /questions
            Method: get
            ApiId: !Ref MyApi

  GetGeoSummaryFunction: 
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: questions/getGeoSummary/            
      Handler: app.handler
      MemorySize: 128
      Description: Returns list of geohashes and scores for single question
      Policies:
        - DynamoDBReadPolicy:
            TableName: !Ref QuestionsTableName      
      Environment:
        Variables:
          AWS_NODEJS_CONNECTION_REUSE_ENABLED: 1
          TableName: !Ref QuestionsTableName
      Events:
        GetQuestions:
          Type: HttpApi
          Properties:
            Path: /geoQuestion
            Method: get
            ApiId: !Ref MyApi

  ## Lambda functions
  ProcessQuestionFunction:
    Type: AWS::Serverless::Function 
    Properties:
      CodeUri: questions/processQuestion/
      Handler: app.handler
      MemorySize: 128
      Timeout: 10
      ReservedConcurrentExecutions: 1
      Environment:
        Variables:
          TableName: !Ref QuestionsTableName      
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref QuestionsTableName 
      Events:
        MySQSEvent:
          Type: SQS
          Properties:
            Queue: !GetAtt QuestionsQueue.Arn
            BatchSize: 10

  ## SQS queues
  QuestionsQueue:
    Type: AWS::SQS::Queue

  GeoAnswersQueue:
    Type: AWS::SQS::Queue

  StarAnswersQueue:
    Type: AWS::SQS::Queue

  ## DynamoDB table
  AnswersTable:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: !Ref AnswersTableName
      AttributeDefinitions:
      - AttributeName: PK
        AttributeType: S
      - AttributeName: SK
        AttributeType: S
      KeySchema:
      - AttributeName: PK
        KeyType: HASH
      - AttributeName: SK
        KeyType: RANGE
      BillingMode: PAY_PER_REQUEST    
      StreamSpecification:
        StreamViewType: NEW_AND_OLD_IMAGES       

Outputs:
  APIendpoint:
    Description: "HTTP API endpoint URL"
    Value: !Sub "https://${MyApi}.execute-api.${AWS::Region}.amazonaws.com"